Unloading valve for oil well pumps and the like



Aug. s, 195o R. L. CHENAULT UNLOADING VALVE FOR OIL WELL PUMPS AND THE LIKE Filed Dec. 6, 1946 R16 Gttorneg 3 Sheets-Sheet l ..-----:=bmwmmwwmwmwmmm 'hzhd mmmmgmmlmmm lil.

n...wlirnlmmmmmmmmmmwmmmm Aug. 8, 1950 R. L. CHENAULT UNLOADING VALVE FOR OIL WELL PUMPS AND THE LIKE 3 Sheets-Sheet 2 Filed Dec. 6, 1946 f@ L. m6521237? 5 Awww/wh Z/H iwf: l 2

' H16 Gttotneg Aug- 8, 1950 R. L. cHENAuLT 2,517,841

UNLOADING VALVE EoR oIL WELL PUMPS AND TEE LIKE Filed Dec. 6, 1946 3 Sheets-Sheet 3 Zmventor Ray L. Chema/t E ,ang

R18 v Gitorneg Patented Aug. 84, 1950 UNLOADING'WALVE Fon .OIL WELLPUMPS .AN-n THE LIKE "Roy" L. 'nenalt,`"ranberry Township, Venango County.; iaeassisnorio Oil Well-Supply 'Company? a corporation of New Jersey :Application Deoopibor 6, 1946,'Seria1 Nos 714,390

l'lliis invention roiatostogas-liftoil Well. pumps fand.. more. particularly io "an uploading valve therefor.

liioil Well pumps embodying iwoastrines of tubing which `utilizeygas pressure to raise .the .-.nuid, there is .a tendency forsacolumnof'fluid to build up .in the inner and outer .strings oitub.- ing-.employed insuch` devices during long periods of shut down. When .this occurs, .excessively high gas pressure is .required vto dislodge .the zool-umile of fluid and-force vthem-up throughthe inner string of tubing before the sofcalled ffgas `:liftsiusger oon bo oseraiodin the usualv manor with normal, ses pressurelKiokfoii. valves ...of- ,the type .which open` by a. telescoping action when the tubing restsv on bottom' have previously :neenpr-oposed and tried for this purpose but they have not proven vsatisfactory when used near Ithebottoin of thetubing because they. sometimes Ac ipennn the down-stroke .of vthe tubing as aresult of friction or the cups in their .respective barrelsl` llAccordingly.it is an object of thepresent in,- -ventionto .provide an unloading valveior-jgas lift `,oil-.well pumps whichais subject toposi-tive .control. l .It is a fur-ther. object of ythis invention .to -prov-ide ran,unloading valve for.. gas lift oil well pumps -vzhich is vsimple in design and ruggedand durable in operation.

-The foregoing and further obiectsvzill .heapparent A'from the following .specification when :read in ooiiunotion with thoattaohed drawings, :wherein:

Figure -1 .is .a view partially in-elevation and partially .in sectionof a gas lift oil well pump embodying the valve .ofthe present invention;

YFigure@ is a view in section of the new unit pr .my presentinvention arranged above the upf por ohe'ok valve;

` Figure 3 is a sectional view ofthe valve chest;

".Theinnerstring is adapted to be reciprocated py. aspiston and cylinder, a portion of which is kindicated.generally at 8. The stationary string ottubing @carries at its lower end a valve-chest oams-26 and'22 carried by the reciprocating string Figure 4 is a view in vertical section of lower Lend of the pump and displacement chamber;A

Figure 5 is a horizontal section on .the line V-V .of Figure 3; i

'Figure '6 is` a horizontal section on the line of Figure 3; and s Figure 7 is a schematic .arrangement of 'gas .supply lines and valves, at upper .end of the well. In Figure 1, I have showna gas lift oil Well pump of the type disclosed and, claimed in my 'Patent No. 2,356,504, granted August 22, 1944. This arrangement comprises essentially an 'outer string of casing '2 in which is, concentrioally dis.- 7posed a stationary string-of tubing 4 .and an in- .porrooiprooatorv and education. stripe of pipe'.

` additional, 'intermediate cam n .49,.irom which is suspended a displacement chamber l2. there is a conventional screen I4. .the valvechest 'are upper and lower ball valves Below the displacement chamber, Disposed in i6 andy I8 adapted to be unseated alternately in normal pumping operationsby upper and.. lower 5. Also. carried by the string'S. and intermediate hecarns 2B and-22 arevsealing members 24 so 'that' the only communication vbetweenthe upper and lower ends of the valve chest is through passageways-.ZB controlled by ball valves B6. Com- .Inunication from the casing 2 to the Aannular ment chamber I2 into the screen I4 and rvhas at its. lower-.end-a. check valve 32.

.A check valve 36 -is disposed inthe inner pipe above the valve-chest. Such a valve has been vfound tov be highly desirable in most cases, as it permits utilization of the energy of expansion of thegasin the pipe after the supply lof gas is shut on? and the displacement chamber is vented to the casing by the exhaust valves. However, when such a check valve is inserted in the inner pipe 6, unloading of a column of fluid therefrom necessitates excessvegas pressures.

AIn orderto overcome this difficulty, I utilize an between lthe cams 2li and 22 and have provided the special unloading valve 4t of this'invention. The intermediate cam 2i and the upper cam 2U are so relatively disposed as to unseat the upper and lower valves l5, and I3 when the inner pipe 6 is 'lowered `to its lowermost position. The unloading valve ,'45 is inserted in the inner pipe 6 above the check valve 36 to permit unloading of a head of fluid therefrom. The valve 40 consists of a valve bore '5B providing -a further unobstructed passageway for uid through the inside of the inner ip ip'e 5.

' At vthe upper end of the tubing 4 Vbelow the annulus between the inner pipe 6 and the tubing 4 simultaneously by opening valves 64 and 10 and closing valve l2.

If due to a shut down columns of uid have built up in the inner pipe and the annular space between the pipe, such fluid may be displaced in the following manner. The inner or reciprocatory string of pipe is lowered to unloading position to unseat valves It and I8 by bringing cams 2l] and 2l into contact therewith. This permits the fluid contained between the inner string of pipe and the tubing to be exhausted to the casing through passages 28 and 30. Then by admitting gas to the inner string (it being understood that gas pressure is normally applied constantly to the annular space between the inner and outer strings), an unbalanced condition is created whereby the pressure in the inner string 6 is greater than in the annular space between string 6 and tubing 4 which automatically lifts ball valve V 4G to permit the column of fluid to flow through ;-l

passage 44 to the annular space between the inner and outer strings of the tubing. Due to valves I6 and I8 being unseated by upper cam 2U and intermediate cam 2l, the iluid displaced from the inner string flows downwardly through passages 28 and 30 and is discharged into the casing 2 and from thence to the oil pool. After the inner string and the annular space is evacuated,

the inner tube is lifted to its normal upper position permitting upper valves I6 to seat and causing the lower valves i3 to be opened by cam 22. This exhausts the gas pressure to the casing and permits the displacement chamber to fill. After it has filled, the inner tube is lowered to its normal lower working position whereby the upper valves l are opened and the lower valves I8 are closed. This admits the gas pressure to the displacement chamber through passages 28 and 3l to force the fluid upwardly from the displacement chamber into the inner tube and thence to the surface.

While I have shown and described one specic embodiment of my invention, it will be understood that this embodiment is merely for the purpose of illustration and description and that various other for-ms may be devised within the scope of my invention, as defined in the appended claims.

I claim:

l. Apparatus for pneumatically pumping liquids from wells including an inlet for gaseous fluid under pressure, a displacement chamber adapted to be positioned in the liquid in a well, ball check valve means for venting the chamber of entrapped gas to the well, a second ball check valve means for controlling the delivery of gaseous fluid from said inlet to said chamber, a vertically reciprocable eduction tube in communication with the lower part of said chamber and extending therefrom to the top of the well, cam means carried by said eduction tube for operating said valves in accordance with the reciprocation of the tube, whereby when the tube is lowered gaseous fluid is admitted to the displacement chamber and when the tube is raised the displacement cham- 4 ber is vented to the well, a check valve in sald tube above said cam means, and a valve body in said eduction tube above said check valve having a passageway opening to the exterior of said tube and a check valve in said passageway, said valve being operable by the application of higher pressure to the interior than the exterior of said tube.

2. Apparatus for pneumatically pumping liquids from wells including an inlet for gaseous fluid under pressure, a displacement chamber adapted to be positioned in the liquid in a well, ball check valve means for venting the chamber of entrapped gas to the well, a second ball check valve means for controlling the delivery of gaseous fluid from said inlet to said chamber, a vertically reciprocable eduction tube in communication with the lower part of said chamber and extending therefrom to the top of the well, cam means carried by said eduction tube for opening said ball check valves in accordance with the reciprocation of the tube, a check valve in said tube above said cam means, a valve body in said eduction tube above said check valve having a passageway opening to the exterior of said tube and a check valve in said passageway, said last-mentioned valve being operable by the application of higher pressure to the interior than the exterior of said tube and cam means for opening both of said ball check valves when said eduction tube is lowered to its lowermost position.

3. Apparatus for pneumatically lifting liquids from wells including inner and outer strings of tubing adapted to be positioned in a well, a displacement chamber carried by said outer string of tub-ing adjacent the lower end thereof, said inner string of tubing forming an eduction tube for delivering liquids from the chamber to the top of the well, a valve chest carried by said outer string of tubing, an exhaust passage leading from the chest to the outside of the outer string of tubing, a gas inlet passage for admitting gas under pressure to the chest, valve ports and valve port sealing means carried in said chest for controlling fluid flow through said exhaust and inlet passages, an open uid passageway leading from the displacement chamber to the chest, means separate from said valve port sealing means and carried by the eduction tube for opening said valve port sealing means, a check valve in said eduction tube abeve said valve chest, a Valve body in said eduction tube having a passageway opening to the annular space between the said two strings of tubing and a check valve in said passageway, said valve being operable by the application of higher pressure to the interior than the exterior of said tube and means for opening both of said valve port sealing means when said eduction tube is lowered to its lowermost position.

4. Apparatus for pneumatically lifting liquids from wells including inner and outer strings of tubing adapted to be positioned in a well, a displacement chamber carried by said outer string of tubing adjacent the lower end thereof, said inner string of tubing forming an eduction tube for delivering liquids from the chamber to the top of the well, a valve chest carried by said outer string of tubing, an exhaust passage leading from the chest to the outside of the outer string of tubing, a gas inlet passage for admitting gas under pressure. to the chest, valve ports and valve port sealing means carried in said chest for controlling fluid flow through said exhaust and inlet passages, an open fluid passageway leading from the displacement'chamber to the chest, means separate from said Valve port sealing means and carried by the eduction tube adapted upon lowering of said tube to its lowermost position to open both of saidvalve port sealing means, a, check valve in said eduction tube above said valve chest, and a Valve body in said eduction tube having a passageway opening to the annular space between the said two strings of tubing, and a check Valve in said passageway, said valve being operable by the application of higher 4pressure to the interior of said eduction tube than to the space between the said two strings of tubing.

5. Apparatus for pneumatically lifting liquids from wells including inner and outer strings of tubing adapted to be positioned in a well, a displacement chamber carried by said outer string of tubingadjacent the lower end thereof, said inner string of tubing forming an eduction tube for delivering liquids from the chamber to the top of the well, a valve chest carried by said outer string of tubing, an exhaust passage leading from the chest to the outside of the outer string of to the interior of said eduction tube than'to the tubing, a gas inlet passage for admitting gas un- 25 der pressure to the chest, Valve ports and Valve port sealing means carried in said chest for controlling iluid ow through said exhaust and inlet passages, an open uid passageway leading space between the said two strings of tubing, and means for simultaneously admitting gas` under pressure to the interior of said eduction tube and the annular space between said eduction tube and the outerstring of tubing.

ROY L. CHEN AULT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

